Perineal urethrostomy is a surgical technique performed for temporary or permanent urine diversion from the penile urethra in male patients with obstructive urinary outflow disease, extensive trauma or invasive tumor affecting penis and prepuce, to access the urethra or bladder to remove uroliths, and to treat horses affected with hemospermia or hematuria secondary to urethral rents. Perineal urethrostomy has been advocated as the treatment of choice in geldings where hematuria does not resolve with conservative treatment and in stallions with hemospermia caused by urethral defects. Most cases of geldings with hematuria are resolved with a single perineal urethrostomy surgery; however, stallions with hemospermia might need a second surgery. Perineal urethrostomy also enables access to the urinary bladder in male horses with cystoliths following minimal dissection and without accessing the abdominal cavity. The most common complications directly related to this surgery are hemorrhage, urine scalding, and urethral stricture at the surgical site. The aim of this article is to review comprehensively the indications for perineal urethrostomy surgery, illustrate the surgical technique approach, and discuss outcomes and complications.